The invention relates to an electrical contact element and, especially, such a contact element which has especially small dimensions and is provided with a flat terminal pin, which, for example, has a width of 1.2 mm and a thickness of in total 0.64 mm. Such electrical contact elements are, for example, used for connecting electrically operated components or electronic components in a vehicle.
Several of such contact elements are accommodated in a housing of a connector. The housing has accommodation chambers, which are arranged next to each other or above each other, respectively, in a specific pattern and accommodate a contact element, respectively. In this case, the contact element has to be secured against withdrawal. The retainment has also to be able to take up the connection forces acting on the contact elements.
EP 0 821 435 B1 (U.S. Pat. No. 5,989,079) describes an electrical contact element. This comprises a base element, made from a sheet material with a good electrical conductivity. The base element has a conductor contact portion, which comprises, for example, a crimping tab, serving to connect a conductor of a cable or an insulation of the cable, respectively. A base portion, formed box-like in cross-section, follows integrally the conductor contact portion. This base portion comprises an upper wall, arranged opposite to a bottom wall. Furthermore, the upper wall and the bottom wall are connected to each other by two side walls. A flat terminal pin is connected integrally to the base portion and extends away from the conductor contact portion. This flat terminal pin comprises two pin portions arranged one above the other. A material portion projects from the upper wall of the base portion in the direction towards the end portion of the terminal pin, connected to the base portion, which material portion is formed integrally with the base portion and engages between the two opposed pin portions. Thus, a root area, i.e. the area of the flat terminal pin attached to the base portion, should be reinforced. The two pin portions and also the reinforcement portion are made from the same material, namely from a material with a good electrical conductivity.
The base portion is enclosed by a cover, formed also box-like and known also as a locking spring. This is made from a non-corrosive steel and has a lance-like portion, forming an elastic retaining element. This contact element is, for example, accommodated in a contact element accommodation chamber of a housing of a connector and is retained in the same by this lance-like portion by means of engaging behind a projection in the contact element accommodation chamber. A cover in form of a locking spring, enclosing the base element, leads to enlarged dimensions and therefore, to larger distances of the contact element accommodation chambers. Furthermore, by means of the reinforcement no improvement of the strength of the flat terminal pin in the direction to its free end is achieved, as no support is given in this area. Also the material, which is used for the intermediate layer, is relative soft. It consists of a copper material, having a good electrical conductivity.
A miniaturized electrical contact element is, for example, described in DE 42 44 776 C2. The contact element comprises a base element with a conductor contact portion and an insulation crimping portion for the connection to an electrical cable or, respectively, to a conductor thereof, which can, for example, consist of a multitude of individual conductors. The base element comprises further an intermediate portion formed U-like and, further, connected integrally thereto a flat terminal pin. This flat terminal pin is formed of two above each other arranged pin portions. The base element is punched from an electrical conductive sheet. The punched part is then formed such that a flat terminal pin is formed, in which the two pin portions are arranged on top of each other and are press-connected. Hereby, the conductor contact portion and also the insulation crimping portion as well as the base portion are brought into the above described U-shape. The base portion is enclosed by a box-like retaining element in form of a locking spring, which is retained form fittingly on the same. Furthermore, retaining spring arms bent towards the outside, are punched out at the two opposed side walls of the locking spring by means of punching out a U-like cut. The retaining spring arms project over the side walls to the outside. The locking spring is made from an elastic material which is stronger in relation to that of the base element, for example, is made from steel. The retaining spring arms serve to retain the contact element in the corresponding accommodation chamber of a connector housing, i.e. to retain it against withdrawal. The construction with a U-like base element and a box-like locking spring enclosing the same, has the disadvantage, that the dimensions in the cross-section are enlarged. Therefore, the distances of the accommodation chambers, i.e. the pattern dimension, have to be formed correspondingly large in a connector housing. There is, however, the requirement, to further decrease the pattern dimension and therewith, to be able to accommodate more contact elements in a predetermined space in a connector housing.
DE 201 04 233 U1 relates to an electrical contact element, made from a punched sheet part and having a contact in the form of a terminal pin as well as a crimping portion as a conductor contact portion. The terminal pin is arranged to a so-called box-like locking spring, which has a lance for the retainment of the contact element in a housing.
DE 42 00 109 A1 (related to U.S. Pat. No. 5,445,541) relates to a contact element with a conductor contact portion in form of crimping tabs and a support body portion attached thereto, for the axial retainment of the contact element in a connector housing. The flat terminal pin consists of two above each other arranged pin portions, which are bent starting from a punched sheet part in such a way, that they cover each other. Between the conductor contact portion in form of crimping tabs and the contact portion formed as a flat terminal pin, the support body is arranged, which is formed by tabs. This support body is engaged behind by a projection on the connector housing in the assembled condition. This projection is part of a locking arm, formed on the connector housing in an elastic manner.
DE 199 22 560 A1 describes a contact element, which comprises a base portion formed integrally with a conductor contact portion. On the base portion a separately manufactured terminal pin made from a solid material can be attached. For this, it has a correspondingly formed connection portion. Additionally, a retaining element in form of a box-like locking spring is provided, which encloses the base portion and has a lance-like and elastic retaining portion, forming a support edge. The terminal pin is solid and has in cross-section a square portion. The base element together with the integrally formed-on contact portion and the terminal pin separated therefrom are, preferably, manufactured from a copper alloy. The retaining element in form of a fixing sleeve arranged thereto, can be used to additionally stabilize the connection of the terminal pin with the base element.